毛澤東源自於黑格爾／馬克思辯證法的「一分為二」，在六十年代中 國成為反右鬥爭的說法；六十年代受到毛派左翼思想影響的當代法國思 想家洪席耶（Jacques Rancière）與巴迪烏（Alain Badiou），其後期思想皆 展現對於「一分為二」的不同演繹。「一分為二」的問題在於如何「計算為 一」，也就是「一分為二」的矛盾如何被實體化為內部疆界，政治主體如 何被「計算為一」，以及作為純粹否定性運動的「一分為二」如何可能重 構「計算為一」的邏輯。本文處理洪席耶與巴迪烏「計算為一」與「一分 為二」之詮釋歧義。他們所試圖回應的問題是：被計算為「一」的主體是 否已經被某種觀念性結構的「一」所決定？是否必然被納入具有統合與 同質的形上學理念、政黨、國家或是資本的穩定權力結構？政治主體如 何能夠透過「一」的出現而挑戰原本「一」的結構，甚至重組在地的話語 邏輯？洪席耶與巴迪烏二人分別提出了「空」（le vide; void, empty space）的 概念以置疑「計算為一」的穩定框架，也透過「空」而演繹出「一分為二」 的矛盾辯證。不過，二人對於「空」的詮釋有明顯差距：洪席耶的感受機 制的「一分為二」，讓他分析了不同話語理性的歧義，以及透過詞語內部 分裂所顯現的間距與差異，使得分歧的獨一感受得以出現，而構成了非 共識的公共空間；至於巴迪烏命名體系切割機制的「一分為二」，則是持 續從既定邏輯撤離的辯證運動，任何命名都銜接了無法計算而不可見的 「空」，而獨一性便基於這個「空集合」的「非空間」而得以出現，這就是 巴迪烏所設想的獨一性平等出現之共產社會。本文指出，洪席耶與巴迪 烏的詮釋差距以及他們的共同關注，一則展現了當代法國思想界的特殊 光譜，再則透過他們的分析，也可以協助我們進一步重新思考二十世紀 歷史過程中政治主體的難題以及平等與公共的根本意義。

Mao Zedong’s concept of “one divides into two,” derived from Hegelian/ Marxist dialectical logic, was influential among French leftist thinkers in the 1960s, including Jacques Rancière and Alain Badiou. While “one divides into two” turned out to be a slogan in China used for political purges in the 1960s, it left a different trace on the philosophical thoughts of Rancière and Badiou in their later developments. The stake of the issue here is whether the division of “one” into “two” is a process of internal partition based on the fixated ideological positions, whether the count of the subject as “one” has already been prescribed and implicated by certain conceptual structure of the One, be it God, Nation, Party or the Capital, or whether one dividing into two is a constant happening in the dialectic movement of the matter. Both Rancière and Badiou proposed the concept of the void (le vide) to disrupt and to relocate the given logic of the count through the dialectic process of “one divides into two.” Their interpretations of the “void,” however, point to different directions. For Rancière, the partage of the sensible indicates the sharing and partaking of the whole as one part, a part that is partitioned within the whole, with a given location. The void between the counted part and the uncounted part, part des sans-part, is the écart—the gap, the empty space, interval, difference—inscribed within the logos where politics begins. For Badiou, counting as one is always already within the regime of cut and is at the edge of the void. The void is the horlieu or non-lieu, or the empty set in the topological sense, which allows something new to happen. This paper examines how Rancière’s and Badiou’s philosophies diverge on the concept of the void while at the same time provide their re-definition of radical equality and the common.